This is how it was up to v2.1.2 included (changed in v2.1.4 onward).
I added a benchmark that has 3 subscribers running and increase
the number of publishers: 1, 2, 5 and 10. This is the comparison
between the pre-PR and post-PR:
```
benchcmp old.txt new.txt
benchmark old ns/op new ns/op delta
Benchmark___BumpPubCount_1x3-16 396 385 -2.78%
Benchmark___BumpPubCount_2x3-16 495 406 -17.98%
Benchmark___BumpPubCount_5x3-16 542 395 -27.12%
Benchmark__BumpPubCount_10x3-16 549 515 -6.19%
benchmark old MB/s new MB/s speedup
Benchmark___BumpPubCount_1x3-16 717.27 737.54 1.03x
Benchmark___BumpPubCount_2x3-16 574.31 699.02 1.22x
Benchmark___BumpPubCount_5x3-16 524.35 718.80 1.37x
Benchmark__BumpPubCount_10x3-16 517.26 551.53 1.07x
```
It is inline with what the user reported, seeing a 20% drop in performance
when going from 1 publisher to 2. But, as we can see, the difference
between go channel and cond variable reduces with the increased number
of publishers after a certain number.
I am not sure of the performance impact on other situations, so this
PR is more of a proposal than a fix.
Resolves#1786
Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
7b116379cb